EP 1 248 929 B1 discloses a plastic core container reinforced with a fiber plastic composite as the inner plastic casing for storing liquid and/or gaseous media under pressure. The core container has one of more fittings in the neck part and/or the bottom part and/or the cylindrical container part. At least one fitting is made to hold a screw-on pressure line feed having a cylindrical or conical thread, such as, for example, a valve or a pipeline connection.
In the connection shank of the plastic core container, a cylindrical insert with a collar end extending peripherally or enveloping on the end of the connecting shank is mounted as the collar part. At least two seals are arranged such that at least one seal is located between the insert and the inside surface of the plastic connection shank of the plastic core container, and at least one other seal is located between the insert and pressure line feed. This arrangement ensures a high level of long-lasting tightness on the fitting even under extreme, cyclic thermal and mechanical operating stresses. Due to the sharp deflection site of the first inner plastic casing in the direction of the collar part by approximately 90°, it cannot be precluded that as a result of the sharp deflection site harmful stress peaks will occur. Although the outside support ring between the outer and inner plastic casings within the gap opening formed thereby tapers conically or in the manner of a wedge to the outside, the resulting support takes place only within the essentially horizontally running or extending contact region of the two plastic casings. As a result, relative movements damaging the plastic can occur between the casings in the contact region during operation of the device.
DE 197 51 411 C1 discloses a composite pressurized container for storage of gaseous media under pressure with a plastic liner as the inner or first plastic casing, with two neck pieces located in the neck region and with a winding of a fiber composite material reinforcing the liner as the second plastic casing. In the neck piece holding the gas check valve, a clamp ring can be screwed into this neck piece. The outer casing has a threaded section adjoined by an unthreaded, truncated cone-like section. The annular groove is located between the internal threaded sections of the neck piece for holding a gasket extends radially into the neck piece and on the outside of the neck piece. In the region adjoining the collar, the arrangement is provided with at least one bead extending radially to the outside over the entire periphery. Likewise, as in the above solution, the wedge-like taper of the outside support ring extends only along the inner peripheral region on the neck piece along a horizontal plane formed by the liner and deflected in turn at a sharp right angle, and ends in the collar part which encompasses the gas supply via the valve. This very effective sealing solution uses correspondingly great technical effort with several components for its implementation.